You are right, Xbox music app still needs hard work, but you me and all of us must admit that the last update make the app better, the first time I feel a different in the experience. Next update will come soon, so we shall wait

Thanks for the confidence guys - as of now its driving me nuts!
One other point I've noted is that when a track is playing the lock screen changes to a stock image for that artist (ie not the one I embedded in the MP3) but when you go into the app the album cover & background are missing!

I have a feeling its got something to do with whether that track appears in the Xbox Music cloud library (many of mine don't) so even though I've embedded an MP3 image its still looking for one in the cloud, if it doesn't find one it doesn't use my default image but instead adds a blank!!